On my 900F I did the so called "shifter mod" to prevent the missed shift into third gear. This mod allows the shift shaft to rotate that little extra bit to allow everything to fall into place instead of popping out. The mod works. I haven't missed the shift into third yet (6,000+ miles) with the bike.
The goal pic taken from the 1100f.net site:
And the grinding I did on my bike:
Stock:
My work:
I don't worry about doing this with my 82 CBX since shifting from 4th to 5th isn't done under power (hey, I am in America!!), but it was well worth it on the 900. I remember as a youngster back in the day on my 750F blowing that shift into third on a regular basis.
Hope this helps.
Steve